As used herein, the term “revenue meter” refers to an electricity meter which is typically installed by an electric utility at a customer's site for the purpose of measuring the electricity usage of the customer for billing purposes. As is well known by those skilled in the art, revenue meters are generally mounted at a customer's site on a substantially permanent basis, as they are typically “sealed” in place in a socket which is permanently mounted at the customer's site. Accordingly, the term “revenue meter”, as used herein is not intended to include meters which are not intended to be socket mounted on a substantially permanent basis. In particular, meters, of the type which include leads for connecting to the circuit being measured are not considered to be revenue meters.
Induction-type watt hour revenue meters typically employ a pulse initiator which generates pulses in proportion to the rate of rotation of a meter disk. These generated pulses are transmitted to electronic registers for deriving current, voltage, power and/or time of use energy consumption.
Various types of solid state polyphase electronic revenue meters are also in common use today. These polyphase electronic revenue meters, which monitor electrical energy consumption and record or report such consumption in kilowatt hours, power factor, KVA, and/or reactive volt amperes, typically employ solid state components, and may utilize analog-to-digital converters to provide digital data rather than pulse data from which various demand/consumption indicators can be extracted.
It is also well known to provide solid state electronic revenue meters which may be configurable for installation in any one of a variety of single or multiphase electricity distribution systems. One example of a solid state electronic watt hour revenue meter is disclosed in U.S. Pat. No. 5,059,896, issued to Germer et al.
An example of a solid state electricity demand recorder which may be used in conjunction with a conventional watt hour meter is disclosed in U.S. Pat. No. 4,697,182, issued to Swanson.
Various ancillary equipment and diagnostic techniques are utilized by service personnel during installation of these revenue meters in an attempt to insure and confirm that the installation of revenue meters is being done correctly. In particular, such ancillary equipment includes a variety of meters, which are not revenue meters, as they typically include, or are adapted to include, cables for connecting them to the circuit being measured. Ancillary equipment used for this purpose is not intended to become a permanent part of the electric circuit, and it is not adapted to be plugged into a meter socket for such purpose. Further, while such equipment can be used to measure electric parameters between two or more points, they require manual intervention to determine the points between which such measurements are made. A revenue meter, on the other hand, is plugged directly into a socket which has been wired to the customer's permanent electric service. Accordingly, when a revenue meter is plugged in, there is no manual intervention to determine what will be measured, as such determination will have been made when the meter socket was wired into the system. Accordingly, while the ancillary equipment of the prior art can be used to determine whether or not the socket has been wired correctly, manual intervention is required. In addition, such ancillary equipment typically required manual interpretation of the results of the measurements made by their users. Consequently, many installation checks, such as polarity and cross-phase checks, are derived on site by field personnel and are therefore dependent upon the knowledge and competence of those personnel.
While various diagnostic equipment is available for use by field personnel during installation and periodic maintenance, a need exists for an integral apparatus which automatically and periodically performs a standard series of system and installation diagnostics without interrupting the operation of the meter. In addition, there is a need for periodic self-checks of the meter to determine and record the occurrence of selected pre-defined fatal and non-fatal errors in the meter's operation.
In addition, although there are revenue meters available which may be adapted for use in more than one type of electrical service, one drawback of these revenue meters is that the customer often must program the service type into the meter prior to installation. This pre-installation programming of multiple service revenue meters tends to limit their multiple service capability.